Though Patrick Bateman may have become the fictional poster boy for psychopaths everywhere, the reality is that not everyone who qualifies as psychopathic would be at home in a Bret Easton Ellis novel. There are in fact non-violent psychopaths, and researchers believe they may have figured out what distinguishes the brains of these more pleasant individuals from their criminal counterparts.
Psychopathy is a complex condition that consists of several traits, such as a lack of empathy, an inability to connect emotionally to others, and uncontrollable impulsivity. Studies have shown that impulsivity ratings are the single most reliable predictor of violent criminal activity among psychopaths, indicating that those who most strongly display this particular characteristic are the most likely to fit the Bateman mold.
To understand how the brains of violent psychopaths are wired, researchers recruited 14 psychopathic criminals and 20 non-criminals who scored highly on psychopathy tests. Since previous research has suggested that imbalances in a brain area called the ventral striatum – which forms part of the reward circuit – are strongly associated with impulsivity and aggression, the study authors focussed their attention particularly on this part of their subjects’ brains.
Participants took part in a game that was specifically designed to activate the ventral striatum by messing with players’ reward expectations. At the beginning of each round, participants were shown either a green or a red circle, indicating whether or not monetary prizes were available. They were then shown a white circle, at which point they had to press a button as quickly as possible.
The connectivity between the brain’s reward circuit and behavior control regions was significantly altered in criminal psychopaths. Johan Swanepoel/Shutterstock